A method to achieve rapid localised deep heating in a laser irradiated solid density target

摘要

Rapid heating of small buried regions by laser generated fast electrons maybe useful for applications such as XUV radiation sources or as drivers forshock experiments. In non-structured targets the heating profile possesses aglobal maximum near the front surface. This paper presents a new target designthat uses resistive guiding to concentrate the fast electron current density ata finite depth inside the target. The choice of geometry uses principles ofnon-imaging optics. A global temperature maximum at depths up to 50{\mu}m intothe target is achieved. Although theoretical calculations suggest that smallsource sizes should perform better than large ones, simulations show that alarge angular spread at high intensities results in significant losses of thefast electrons to the sides. A systematic parameter scan suggests an optimallaser intensity. A ratio of 1.6 is demonstrated between the maximum iontemperature and the ion temperature at the front surface.